Method for recognizing a fuel type in a diesel engine

Abstract

A method for recognising the fuel type in a diesel engine; the method envisages determining a stoichiometric air / fuel ratio of the last type of fuel used; determining a quantity of fresh air fed to a number of cylinders of the engine; determining a quantity of fuel injected in the cylinders; determining a theoretical air / fuel ratio of combustion according to the quantity of fresh air fed to cylinders, according to the quantity of fuel injected into cylinders, and according to the stoichiometric air / fuel ratio of the last type of fuel used; determining an actual air / fuel ratio of combustion; comparing the theoretical air / fuel ratio with the actual air / fuel ratio; and recognising the fuel type actually used according to the comparison between the theoretical air / fuel ratio and the actual air / fuel ratio.

Description

technical field

[0001] The present invention relates to a method for identifying the type of fuel in a diesel engine, ie in an engine which compression ignites rather than spark ignites the mixture therein. Background technique

[0002] In certain parts of the world (e.g. Brazil), spark ignition internal combustion engines are used with different types of liquid fuels (e.g. pure gasoline, hydrate alcohol, or mixture of gasoline and alcohol) feed. Therefore, for a vehicle driven by a spark ignition internal combustion engine, in order to optimize combustion control according to the type of fuel actually used, it is recommended to use a device capable of recognizing the type of fuel in the tank.

[0003] Currently, modern diesel engines can also run on fuels other than diesel, which is commercially known as "biodiesel" and consists of a mixture of diesel and fuel derived from biomass (eg, vegetable oils such as rapeseed oil). However, within a modern diesel engine, the engin...

Examples

Embodiment Construction

[0015] In the figures, reference numeral 1 generally designates an internal combustion engine of the diesel engine type, ie an engine in which the mixture in it is ignited by compression rather than by spark. The engine 1 is provided with a plurality of cylinders 2 (only one of which is shown in the drawings), each cylinder being connected to the intake manifold 3 through at least one intake valve 4 and connected to the exhaust manifold through at least one exhaust valve 6. Tube 5. The intake manifold 3 receives cool air (ie, air from the external environment) through a throttle valve 7 that is adjustable between a closed position and a fully open position. Leading from the exhaust manifold 5 is an exhaust pipe 8 terminated with a muffler (known and not shown) to release gases produced by combustion into the atmosphere. Furthermore, a recirculation pipe 9 connecting the exhaust manifold 5 to the intake manifold 3 leads from the exhaust manifold 5 and is regulated by a recircu...

technical field

[0001] The present invention relates to a method for identifying the type of fuel in a diesel engine, ie in an engine which compression ignites rather than spark ignites the mixture therein. Background technique

[0002] In certain parts of the world (e.g. Brazil), spark ignition internal combustion engines are used with different types of liquid fuels (e.g. pure gasoline, hydrate alcohol, or mixture of gasoline and alcohol) feed. Therefore, for a vehicle driven by a spark ignition internal combustion engine, in order to optimize combustion control according to the type of fuel actually used, it is recommended to use a device capable of recognizing the type of fuel in the tank.

[0003] Currently, modern diesel engines can also run on fuels other than diesel, which is commercially known as "biodiesel" and consists of a mixture of diesel and fuel derived from biomass (eg, vegetable oils such as rapeseed oil). However, within a modern diesel engine, the engin...

Examples

Embodiment Construction

[0015] In the figures, reference numeral 1 generally designates an internal combustion engine of the diesel engine type, ie an engine in which the mixture in it is ignited by compression rather than by spark. The engine 1 is provided with a plurality of cylinders 2 (only one of which is shown in the drawings), each cylinder being connected to the intake manifold 3 through at least one intake valve 4 and connected to the exhaust manifold through at least one exhaust valve 6. Tube 5. The intake manifold 3 receives cool air (ie, air from the external environment) through a throttle valve 7 that is adjustable between a closed position and a fully open position. Leading from the exhaust manifold 5 is an exhaust pipe 8 terminated with a muffler (known and not shown) to release gases produced by combustion into the atmosphere. Furthermore, a recirculation pipe 9 connecting the exhaust manifold 5 to the intake manifold 3 leads from the exhaust manifold 5 and is regulated by a recircu...

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